Photographic processing apparatus

ABSTRACT

A processing apparatus which comprises a pair of inlet rollers, a pair of outlet rollers, a guide plate forming the bottom of the processing tray and at least one non-driven roller, situated above the bottom and partly or wholly immersed in the processing solution. The peripheral speed of the pair of outlet rollers slightly exceeds that of the pair of inlet rollers, so that a sheet of photographic material is lifted from the bottom when its leading edge reaches the nip of the pair of outlet rollers. Optionally a suplementary roller may be provided, which is frictionally driven by the upper one of the pair of inlet or outlet rollers and which imparts its rotation to the immersed rollers.

United StatesPatent 1 Stievenart et al.

PHOTOGRAPHIC PROCESSING APPARATUS lnventorsz' Assignee:

Filed:

Appl. No.:

Emile Frans Stievenart, Hoboken; Herman Fernand Verbruggen, Berchem, both of Belgium AGFA-Gevaert, Mortsel, Belgium Feb. 20, 1973 333,649

Foreign Application Priority Data References Cited UNITED STATES PATENTS Arnold et al 95/94 R X 6/1965 DeBelder 95/89 R [451 Sept. 3, 1974 3,315,583 4/1967 Hunt 95/94 R 3,465,663 9/1969 Calder 95/89 A 3,667,987 6/1972 Miller 95 /94 R X 3,735,689 5/1973 Smola et al. 95/94 R Primary Examiner-Fred L. Braun Attorney, Agent, or Firm-William J. Daniel 5 7] ABSTRACT A processing apparatus which comprises a pair of inlet rollers, a pair of outlet rollers, a guide plate forming the bottom of the processing tray and at least one nondriven roller, situated above the bottom and partly or wholly immersed in the processing solution. The peripheral speed of the pair of outlet rollers slightly exceeds that of the pair of inlet rollers, so that a sheet of photographic" material is lifted from the bottom when its leading edge reaches the nip of the pair of outlet rollers. Optionally a suplementary roller may be provided, which is frictionally driven by the upper one of the pair of inlet or outlet rollers and which imparts its rotation to the immersed rollers.

u minnow 3 1 SEE! 1 N 3 (AWL 3 mm mm PAI ENIEBsEP 31914 3883.918

SHEET? 0? 3 Fig. 2

1 PHOTOGRAPHIC PROCESSING APPARATUS The present invention relates to a photographic processing apparatus, and in particular to a processing apparatus comprising a container for holding processing liquid and a guide plate which determines the lower boundary of the path for a sheet of photographic material travelling through the processing liquid in the contamer.

The invention is particularly although not exclusively concerned with apparatus for use in the automatic and rapid development processing of light-sensitive or X-ray sensitive photographic films or sheets after exposure. The apparatus according to the invention can also be used for processing image-wise exposed silver halide material by a process according to the United Kingdom Patent No. 1,243,180 filed Oct. 11, 1967 by Gevaert- Agfa N.V. wherein the material is conveyed at substantially constant speed through activating, stabilising, fixing and rinsing stations in succession.

An apparatus allowing an automatic and rapid development of light-sensitive or X-ray sensitive photographic films or sheets has already been disclosed. A description of such an apparatus can be found in the Belgian Patent Specification No. 771,923 filed Aug. 30, 1971 by Agfa-Gevaert N.V.

Although the above-mentioned apparatus is very well suited for processing photographic papers, it may produce unwanted secondary effects when processing photographic or X-ray sensitive sheet materials which are either double-coated or provided with one or more backing layers. The rubbing of said backing emulsion layers against the immersion plate, urging said layers towards the guide plate, may be the cause of scratches whereas for highly sensitive materials a supplementary effect known as pressure sensitizing or desensitizing is produced. This effect consists in an increase or decrease in sensitivity of photographic emulsion layers under the influence of pressure exerted upon it. As in this kind of processing apparatus the sheet to be processed is forwarded through the narrow slit formed by the guide plate and the immersion plate the emulsion layer contacts said underlying guide plate until it is seized by the rollers at the outlet of each station. The sheet areas which have made contactwith the guide plate in the developing station during processing, may be somewhat overor under-developed in some cases.

The present invention aims to provide an apparatus for processing photographic material, without these disadvantages.

According to the present invention, there is provided apparatus for processing photographic material, said apparatus comprising a container for holding processing liquid, means for keeping said container filled with processing liquid up to a predetermined level, first and second pairs of rollers respectively located at an entry end region and at an exit end region of the container for transporting photographic material into and out of processing liquid in'said container, at least one intermediate roller (hereafter called immersion roller) located so that at least part of it is beneath said predetermined level and beneath a plane extending from the nip of the first pair to the nip of the second pair of transporting rollers, said immersion roller(s) furthermore being disposed so that when a sheet of photographic material is driven into the container by' said first pair of transporting rollers the leading end of such sheet will pass beneath such immersion roller(s), at least one guide surface extending beneath and at a spacing from said immersion roller(s) for guiding such leading end towards the nip of said second pair of trans porting rollers, and means for driving saidfirst and second pairs of transporting rollers so that the peripheral speed of the rollers of the second pair exceeds that of the rollers of the first pair.

When apparatus according to the present invention is used the faster peripheral speed of the transporting rollers at the exit end region of the container causes the sheet photographic material to be pulled upwardly against the immersion roller(s), as the sheet is in the course of being transported through the apparatus. As soon as the transporting rollers at the exit end region of the apparatus grip the sheet material, its lower face is therefore moved out of contact with the guide surface. Rotation of the immersion roller(s) against which thesheet is pulled avoids the occurrence of sliding friction between such roller(s) and the sheet.

Preferably the apparatus comprises two immersion rollers, one being located in the entry end portion of the said container and the other being located in the exit end portionof such container. I The immersion roller(s) maybe mounted for free rotation under tractive force exerted by the sheet material itself, or the said roller(s) may be driven, e. g., from the transporting roller pairs.

"The invention includes an apparatus for processing photographic material, with at least one processing station whichcomprises: V

a. a containerfor holding processing liquid.

b. means for keeping said container filled with processing liquid up to a predetermined level.

c. a guide plate having a concave surface determining the lower boundary of a path for the photographic material which travels through the processing liquid.

d. drive means for transporting said photographic material through the apparatus, said drive means comprising a first pair of pressure rollers located at the-inlet of the processing station, a second pair of pressure rollers located at the outlet of the processing station, and means for driving the pairs of rollers such that the peripheral speed of the second pair of rollers slightly exceeds that of the first pair of rollers.

. a first immersion roller which forwards the material tobe processed, towards the lowest point of the concave surface, and a second immersion roller located between said'first immersion roller and said second pair of pressure rollers making the material follow a path which runs close along the upper portion of the surface of the guide plate towards the outlet of the processing station, both immersion rollers being rotatably journalled in adequate bearings.

lnthe following description the term processing includes any of the steps involved in converting a black and white, X-ray sensitive, infra-red or ultra violet sensitive emulsion, an emulsion which is to be treated according to an activating or stabilizing process, a colour photographic emulsion, etc., into a finished image, whereas the term photographic material" points to all kinds of materials bearing one or more of such sensitive emulsion(s) on sheets or webs, said sheets or webs being made of paper or high polymer substances. I

The invention will be further described hereinafter I with reference to an apparatus for automatically processing photographic material according to a process described in the United Kingdom Patent No. 1,243,180 filed Oct. 1 1, I967 by Gevaert-Agfa N.V. wherein the material is conveyed through activating, stabilising, fixing and rinsing stations in succession. It will be understood, however, that the apparatus according to the invention is not only useful for this particular process, but

can also be used in the treatment of photographic sheet materials in other processing compositions which require the replacement of the liquid in the container by an amount of fresh liquid which is nearly proportional to the area of the material sheet passed through the liquid.

Some embodiments of the present invention are described hereinafter with reference to the accompanyin the processing of photographic or X-ray sensitive mate- I rial and embodying the invention, is illustrated in FIG. 1.

The apparatus 10 comprises a housing 11 with a lid 12. An inlet opening 1 and outlet opening 3 are respectively provided at the front and the rear side of the apparatus. Preferably, the housing rests on three or four set screws for the horizontal adjustment of the same.

As this kind of apparatus may be used for processing a great variety of photographic or X-ray sensitive materials, the number of processing stations may vary between two and four. In the present embodiment, an apparatus provided with four of such processing stations will be described. The processing stations are respectively: the activating station 15, the stabilising station 16, the fixing station 17 and the rinsing station 18. Processing liquid is supplied to the different stations from inverted supply bottles 19 to 22 through a birds fountain level control- The sheet of photographic or X-ray sensitive material is introduced into the inlet slit 1, and advanced through the apparatus by means of pairs of rollers, such as the rollers 40, 41 and 42, 43 in the activating station 15.' After having subsequently passed through the complete processing cycle, the material sheet leaves the apparatus through outlet slit 3.

The rollers of each pair are preferably covered with a resilient material such as butyl rubber or the like and they may be pressed against each other in a known way by means of elastic belts (not shown) tensioned over the plastic roller bearings at each-extremity of the roller shafts so as to hold the latter together. Only the activat ing station 15 and the stabilising station 16 are provided with two pairs of rollers for the sake of reproducibility as the processing steps occurring in these stations are rather critical. By means of the squeeze rollers the processing step is abruptly stopped, whereas the risk of contaminating the processing liquid in the next processing station is also avoided practically.

The processing apparatus is further provided with driven immersion rollers in each station. Thus, immersion rollers 44 and 45 are provided in the activating station 15 which are respectively driven by the free tuming rollers 51 and 50.

The immersion rollers 44 and 45 transport the photographic or X-ray sensitive material through the processingliquid 47 over a guide plate 48 thermostatically controlled by adequate liquid flowing through the channel 46 which is formed by said guide plate 48 and the plate 49.

The immersion rollers 44 and 45 are made of stainless steel, although other materials which are highly polishable and chemically inert are also suitable for the purpose. On the contrary the free turning auxiliary rollers 50, 51 will preferably be made of a material having a rough, resilient surface, showing a sufficiently high friction coefficient to cause the immersion rollers to be rotated by such auxiliary rollers. Said free turning auxiliary rollers are joined to each other by means of a frame 23, 24, 25 or 26 provided with a grip 27, 28, 29

.or 30 permitting the easy removal of the auxiliary roller sets for cleaning purposes.

Each processing station is equipped with an overflow system (not shown) for draining away the liquid, which is carried off and/or exhausted during the corresponding processing step, towards collecting containers 53 to 56 provided with hollow U-shaped transparent handles 57 to 60. In this way the level of the liquid can easily be controlled and the containers are emptied when necessary. I

f A modified processing station is shown in detail in FIG. 2. A sheet 2 of photographic material which has to be processed is introduced into the apparatus through the slit 1 whereafter it is seized by a first pair of rollers 40 and 41, the latter turning in the sense indicated by the arrows. Said rollers drive the sheet of photographic material through the processing solution 47. At a given moment, depending on the speed of travel through said processing solution, the leading end of said sheet of photographic material contacts the immersion roller 44 which will deflect the latter downwards so as to form an angle a with respect to the horizontal. As the processing step continues the leading end of the sheet of photographic material advances along the surface of the guide'plate 48, reaches a second immersion roller 45,'and finally arrives in the nip of a second pair of rollers 42 and 43 for squeezing purposes.

Both immersion rollers 44 and 45 are rotatably jour nalled by means of the extremities of their shafts 63 and 64 respectively in adequate bearings.

As the squeezing rollers turn in the sense denoted by the arrows and have a peripheral speed which is slightly higher than that of the pair of rollers 40 and 41 the sheet of photographic material is lifted up from the guide plate 48 so that said sheetcontinues its movement tangentially to both immersion rollers 44 and 45. The pressure with which the rollers 42 and 43are pressed together is regulated so that the force acting upon the swollen emulsion layer of the sheet of photographic material is reduced to a minimum so that scratches, which might be caused by occasional slipping of the photographic material against said rollers are avoided. Mutual slipping of rollers 42 and 43 can be avoided by the use of interrneshing gears at one extrernity of the respective roller shafts. Processing faults as hereinbefore mentioned, viz. pressure sensitization or desensitization and scratches are greatly reduced by the emodiment described as-sliding friction is replaced by rolling friction and full contact of the emulsion layer with the guide plate is avoided.

For the purpose of thermostatic control, a channel 46 filled with adequate liquid and formed by the guide plate 48 and a plate 49 is provided under each guide plate 48.

Unlike the pairs of rollers 40, 41 and 42, 43 which are covered by a resilient material as e.g. butyl rubber, the immersion rollers 44 and 45 are made of a hard, highly polishable material of high dimensional stability. Preferably stainless steel is used for the manufacture of said immersion rollers.

The amount of liquid carried along with the sheet of photo-sensitive material can either flow away through an opening 61 or be temporarily stored in the container 65 until the level reaches the opening 62, so avoiding drying of the roller 43 such as would give rise to drying streaks on the photosensitive material.

Another embodiment of the invention which is preferred for processing double coated X-ray sensitive material, is illustrated in FIG. 3. g

FIG. 3 is distinct from FIG. 2 in that the processing station (like-the processing stations in the apparatus shown in FIG. 1) is provided with two rollers 50 and 51 each of which rests freely on the upper roller of one pair of driving rollers and on one of the immersion rollers. This is done for the following reason: X-ray sensitive material, having a relative thick emulsion coating on both sides is very vulnerable to friction when it is in a wet condition. In the embodiment of FIG. 1, slight traces of impurities, deposition of sludge, may cause temporary blockage of the immersion rollers with consequent risk of scratching the emulsion layer in contact with them. A free rotating roller 50 or 51 having a more or less rough resilient surface and contacting a driving roller and an immersion roller will force the latter to rotate in the direction of rotation of the driving roller.

Although it is not necessary for the auxiliary rollers to have the same dimensions as the driving or the immersion rollers, the use of auxiliary rollers having at least the same length as the other ones affords some interesting supplementary advantages. Firstly, the presence of a uniform charge which does not act perpendicularlyhas a favourable effect upon the deflection by the immersion rollers in case photographic materials having a very large width are to'be processed. Se! condly, if the auxiliary rollers have a rough covering providing a plurality of holes in which sludge may be collected, the sludge collection can occur over the full length of the rollers.

As in FIG. I the squeezing rollers at the outlet of the apparatus are driven at a slightly greater peripheral speed than with the driven rollers located behind the inlet slit. In a preferred embodiment this greater speed is achieved by making the diameter of said squeezing rollers slightly greater, but other systems may be applied by those skilled inthe art.

In the apparatus as described hereinbefore the amount of processing liquid which is carried off from a processing station by the sheet of photosensitive material during processing and which is proportional to the surface .area of the material, is automatically replaced by the instantaneous supply of fresh solution, so that, notwithstanding the relatively simple construction and working principle of the apparatus an automatic regeneration is easily realized.

From the foregoing it is clear that many variations of the described apparatus may be derived by those skilled in the art. The description is however merely intended as an illustration of the present invention.

The guide plate may present a single guide surface or a plurality of guide surfaces. For example, the guide plate may be corrugated with the corrugation running parallel with or at an inclination to the line of travel of the sheet material so that the latter contacts the crests of the corrugation.

We claim:

1. Apparatus for processing photographic material, said apparatus comprising a container for holding processing liquid, means for keeping said container filled with processing liquid up to a predetermined level, first and second pairs of rollers respectively located at an entry end region and at an exit end region of the container for transporting photographic material into and out of processing liquid in said container, at least one immersion roller journaled for rotation at a level such' that at least an arc of its peripheral surface is beneath said liquid level and beneath a plane extending from the nip of the first pair to thenip of the second pair of transportingrollers, each such immersion roller being disposed so that when a sheet of photographic material is delivered into the container by said first pair of transportingrollers, the leading end of such sheet will pass beneath the same, at least one guide surface extending beneath each such immersion roller for guiding such leading end towards the nip of said second pair of transporting rollers, said surface and the nearest point of each such immersion roller being spaced apart a distance substantially greater than the thickness of said material to be processed, and means for driving said first and second pairs of transporting rollers so that the peripheral speed of the rollers of the second pair exceeds that of the rollers of the first pair, whereby said material after engagement in the nip of said second roller pair is tensioned out of contact with said guide surface and into contact with each said rotatable immersion roller.

2. Apparatus according to claim 1, wherein there are two such immersion rollers, one being located in the entry end portion of said container and the other being located in the exit end portion of such container.

'3. Apparatus according to claim 2, wherein each of said immersion rollers is journaled for free rotation by frictional force exerted by a sheet of material as it is in the course of being transported by said first and second pairs of transporting rollers.

4. Apparatus according to claim 2, wherein means is provided for driving each of said immersion rollers.

5. Apparatus according to claim 4, wherein each of said immersion rollers is driven by an idler roller which is in turn driven by the upper roller of the adjacent pair of transporting rollers.

6. Apparatus according to claim 5, wherein each of said idler rollers has substantially the same length as the rollers with which it is in contact.

7. Apparatus according to claim 6, wherein each of said idler rollers has a rough surface.

8. Apparatus according to claim 7, wherein the idler rollers are supported by a common frame permitting their easy removal as a unit. w

9. Apparatus according to claim 1, wherein said at least one guide surface is constituted by the bottom of said container.

10. Apparatus according to claim 9, whereinat least one said guide surface is concavely curved along the line of motion of sheet material through the container.

11. Apparatus according to claim 1, wherein means is provided for driving said first and second pairs of transporting rollers at equal angular speeds but the rollers of said second pair are of greater diameter than the rollers of said first pair. v

12. An apparatus for processing photographic material with at least one processing station, comprising:

a. a container for holding processing liquid,

b. means for keeping said container filled with processing liquid up toa predetermined level,

0. a guide plate having a concave surface determining the lower boundary of a path for the photographic material which travels through the processing liquid,

d. means for transporting said photographic material through the apparatus, said transporting means comprising a first pair ofpressure rollers located at the inlet of the processing station, a second pair of pressure rollers located at the outlet of the process- 8 ing station, and means for driving the pairs of rollers such that the peripheral speed of the second pair of rollers slightly exceeds that of the first pair of rollers,

e. a first immersion roller which conveys the photographic material to be processed towards the lowest point of the concave surface, and a second immersion roller located between said first immersion roller and said second pair of pressure rollers for guiding the material along a path towards said outlet roller pair, both immersion rollers being rotatably joumalled in fixed bearings at a locus maintaining at least a portion of their periphery immersed in said processing liquid but spaced from the nearest point on said guide plate'a distance substantially greater than the thickness of the material being processed. Y

l3. Processing apparatus according to claim 12,

wherein the first pair oftransporting rollers is so disposed that the nip of the rollers of that pair is below the predetermined level of processing liquid in the container, whereas the second pair of rollers is so disposed that the nip of the rollers of that pairis' above the pre- 

1. Apparatus for processing photographic material, said apparatus comprising a container for holding processing liquid, means for keeping said container filled with processing liquid up to a predetermined level, first and second pairs of rollers respectively located at an entry end region and at an exit end region of the container for transporting photographic material into and out of processing liquid in said container, at least one immersion roller journaled for rotation at a level such that at least an arc of its peripheral surface is beneath said liquid level and beneath a plane extending from the nip of the first pair to the nip of the second pair of transporting rollers, each such immersion roller being disposed so that when a sheet of photographic material is delivered into the container by said first pair of transporting rollers, the leading end of such sheet will pass beneath the same, at least one guide surface extending beneAth each such immersion roller for guiding such leading end towards the nip of said second pair of transporting rollers, said surface and the nearest point of each such immersion roller being spaced apart a distance substantially greater than the thickness of said material to be processed, and means for driving said first and second pairs of transporting rollers so that the peripheral speed of the rollers of the second pair exceeds that of the rollers of the first pair, whereby said material after engagement in the nip of said second roller pair is tensioned out of contact with said guide surface and into contact with each said rotatable immersion roller.
 2. Apparatus according to claim 1, wherein there are two such immersion rollers, one being located in the entry end portion of said container and the other being located in the exit end portion of such container.
 3. Apparatus according to claim 2, wherein each of said immersion rollers is journaled for free rotation by frictional force exerted by a sheet of material as it is in the course of being transported by said first and second pairs of transporting rollers.
 4. Apparatus according to claim 2, wherein means is provided for driving each of said immersion rollers.
 5. Apparatus according to claim 4, wherein each of said immersion rollers is driven by an idler roller which is in turn driven by the upper roller of the adjacent pair of transporting rollers.
 6. Apparatus according to claim 5, wherein each of said idler rollers has substantially the same length as the rollers with which it is in contact.
 7. Apparatus according to claim 6, wherein each of said idler rollers has a rough surface.
 8. Apparatus according to claim 7, wherein the idler rollers are supported by a common frame permitting their easy removal as a unit.
 9. Apparatus according to claim 1, wherein said at least one guide surface is constituted by the bottom of said container.
 10. Apparatus according to claim 9, wherein at least one said guide surface is concavely curved along the line of motion of sheet material through the container.
 11. Apparatus according to claim 1, wherein means is provided for driving said first and second pairs of transporting rollers at equal angular speeds but the rollers of said second pair are of greater diameter than the rollers of said first pair.
 12. An apparatus for processing photographic material with at least one processing station, comprising: a. a container for holding processing liquid, b. means for keeping said container filled with processing liquid up to a predetermined level, c. a guide plate having a concave surface determining the lower boundary of a path for the photographic material which travels through the processing liquid, d. means for transporting said photographic material through the apparatus, said transporting means comprising a first pair of pressure rollers located at the inlet of the processing station, a second pair of pressure rollers located at the outlet of the processing station, and means for driving the pairs of rollers such that the peripheral speed of the second pair of rollers slightly exceeds that of the first pair of rollers, e. a first immersion roller which conveys the photographic material to be processed towards the lowest point of the concave surface, and a second immersion roller located between said first immersion roller and said second pair of pressure rollers for guiding the material along a path towards said outlet roller pair, both immersion rollers being rotatably journalled in fixed bearings at a locus maintaining at least a portion of their periphery immersed in said processing liquid but spaced from the nearest point on said guide plate a distance substantially greater than the thickness of the material being processed.
 13. Processing apparatus according to claim 12, wherein the first pair of transporting rollers is so disposed that the nip of the rollers of that pair is below the predetermined leveL of processing liquid in the container, whereas the second pair of rollers is so disposed that the nip of the rollers of that pair is above the predetermined level of processing liquid in the container. 